Auxin Gradients Are Associated with Polarity Changes in Trees
Eric M. Kramer,1*
Michael Lewandowski,3
Satvik Beri,1
Jessica Bernard,3
Matthew Borkowski,1
Michael H. Borkowski,1
Laura Ann Burchfield,1
Brenda Mathisen,1
Jennifer Normanly3
Models of plant growth and development propose that changes
in cell polarity are mediated by gradients of the plant hormone
auxin. With use of gas chromatography-mass spectrometry, we
measured the redistribution of endogenous auxin in stems of
quaking apen trees (Populus tremuloides) after wounding. Persistent
(lasting at least 24 hours) auxin gradients were observed in
the region of the cambium where cell polarity was changing.
A computer model of the auxin redistribution shows agreement
with measured concentrations.
3 Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA.
2Centre for Plant Integrative Biology, University of Nottingham, Loughborough LE12 SRD, UK.
* To whom correspondence should be addressed. E-mail: ekramer{at}simons-rock.edu
